Diabetic and eyes got damaged called as RETNOPATHY. Underwent laser treatment, but not fruitful. Suggest?

Hi,
My father is sufferring from Diabities and due to this his eyes got damaged.
Currently Diabities is under control but EYES got damaged badly.As per my knowledge disease called as RETNOPATHY.
Under went laser treatment twice but not fruitful.
Request you to please advie or let me know the soultion for the same or suggest good doctor for the treatment.

I feel useful tips are as follows:-- Most important factor which governs Retinopathy is glucose control. Rosy part of the story is that sustained glucose control even reverses Retinopathy. - Control of BP is and lipids is also important.- Tobacco use in any form, if being done, needs to be stopped totally.